For CPUs : AMD athlon II x2 250 yes, noMBOs: need something with 2 x PCIe x16 yes,noDo,the MBO, have to have onboard GPU, or not??? Where do you connect monitor if you dont have on board GPU?POWER: how big do I have to have? more than 800W or more than 1000W

What do you use?DO I have to worry about current that goes through a MBO to 2x GPUs?

What mining software to use on multi GPU rig?Is it better to be in mining pool or to mine by me self...

For CPUs : AMD athlon II x2 250 yes, noMBOs: need something with 2 x PCIe x16 yes,noDo,the MBO, have to have onboard GPU, or not??? Where do you connect monitor if you dont have on board GPU?POWER: how big do I have to have? more than 800W or more than 1000W

CPUs: AMD Sempron 140 (probably the cheapest available CPU) will do fineMBO: no PCIe x16 needed for mining, x8 works too. OnBoard GPU is useless, connect monitor to one of your 5870sPSU: for dual-5870 650W will be more than enough, 12V-rail has to handle enough load though (calculate ~200W per GPU and you're good).